NX uses code from the X.org X11 server which is prone to multiple
vulnerabilities.

Background

NoMachine's NX establishes remote connections to X11 desktops over
small bandwidth links. NX and NX Node are the compression core
libraries, whereas NX is used by FreeNX and NX Node by the binary-only
NX servers.

Security is a primary focus of Gentoo Linux and ensuring the
confidentiality and security of our users machines is of utmost
importance to us. Any security concerns should be addressed to
security@gentoo.org or alternatively, you may file a bug at
http://bugs.gentoo.org.